The New South Wales Government has unveiled its new rail timetable that will come into force from next month.

The Transport Minister Gladys Berejiklian says train customers will benefit from more than 1000 additional weekly services, of those 600 will be express.

"This timetable also sets us up for the future, it considers for example what it means when the south west rail line is completed, when the north west rail line is completed," she said.

Ms Berejiklian says the vast majority of people will receive improved services.

However, Sydney Trains boss Howard Collins says those using Kogarah and Rockdale stations in the city's south will see slightly longer travel times.

"They will gain some minutes but more importantly it's the reliability of the service that we want to improve upon here," he said.

But the opposition's transport spokeswoman Penny Sharpe says that the change will leave many people worse off.

"Kogarah station is the 17th busiest station in the network," she said.

"Half of its services have been slashed.

"For the Blue Mountains particularly, no stop at Westmead.

"Westmead is a huge health precinct and education precinct and there are services cut from that stop."

'A great outcome for western Sydney'

The new timetable has been welcomed by the Sydney Business Chamber, which says it will increase access to major centres such as Parramatta CBD.

Its Western Sydney Director David Borger says the new schedule will allow workers from the south west to get to Parramatta and Westmead without changing services.

"Its a great outcome for western Sydney residents to see the NSW Government increasing the number of services, and express services, between the western Sydney heartland cities of Penrith, Blacktown, Liverpool and Campbelltown to the Sydney CBD," he said in a statement.

The new timetable has also been applauded by the industry group the Tourism & Transport Forum (TTF).

TTF Deputy CEO Trent Zimmerman says it will be more attractive to commuters because of a move towards scheduling services at regular intervals.

"In TTF's major report, Improving Your Commute, we urged transport authorities to move to 'turn up and go' services, which allow commuters to know that trains will arrive reliably at set intervals," he said in a statement.

"We are pleased that this major re-write of the NSW train timetable is taking Sydney trains in that direction."

The TTF has also welcomed additional services to Sydney Airport saying the line is very congested at peak times.